Single white star-like light traveling from north to south observed for about 8 to 10 seconds before disipating

I was sitting in a chair outside my house facing east, when I looked up at about 75-80 degrees, almost straight up and saw what appeared to be a star moving slowly from north to south. It covered an arc of about 10-12 degrees and then rapidly disipated. I checked Heavens-Gate to see if an Iridium flare was due in that region of the sky, but it nearest event was expected about 30 degrees to the west and on another course. I was kind of surprised, as not a lot of stars were visible as it was a typical hazy evening.

((NUFORC Note: The description seems consistent with the sighting of a satellite in polar orbit, but that is only a guess. However, we have no explanation as to why an orbitting object would disappear from sight, the way a satellite coursing to the east would do. PD))